Many older adults believe that the ravages of oral disease are an inevitable consequence of aging. Further, barriers to care limit access to self-help knowledge and the failure to seek care exacerbates the problems that develop. A major gap is the lack of a measure that captures the concept of older adult's cognitive and emotional representation (perception) of oral diseases. Such a measure can be an effective mediator in causal studies and its domains can be targeted for interventions. The concept is based on Leventhal's Common Sense Model of Self-Regulation (CSM). Emerging research in medicine shows the effectiveness of interventions based on the concept. Our group has previously developed a standardized measure of illness perception of dental caries in childhood based on the CSM framework. In the proposed study, we will use our experience to develop a new measure for older adults who have single and multiple oral diseases. The proposed work will utilize constructs from prior measures found to be valuable in the medical field, i.e. the Revised Illness Perception Questionnaire (IPQ-R) and the Multimorbidity Illness Perception Scale (MULTIPLeS). Such an integrated measure does not exist for either dental or medical diseases. The following aims will be investigated using mixed methods: 1) examine the factor structure of the new Revised Illness Perception Questionnaire for Dental use (IPQ-RDE) in older adults; 2) test the psychometric properties of the IPQ-RDE in terms of validity and reliability; and 3) establish the mode of delivery (in-person interview vs. paper-pencil). The study will be conducted in two phases: Phase I will be a qualitative approach with cognitive interviews of 20 older adults (= 62 years) to refine the IPQ-RDE, focusing on clarity, content, readability, and response options of the items; Phase II will be quantitative methods to assess psychometric properties of the IPQ-RDE in 200 older adults, and assure the comparability of interview and paper-pencil mode of the instrument in a smaller sub-sample. Validity assessments will include: Construct to validate the domains of the IPQ-RDE with coping, social support, and depression measures; Concurrent to validate with clinical oral health outcomes (caries, root caries, periodontal disease) from dental screening, and the perceived condition of teeth; Discriminant to distinguish according to socioeconomic status, medical/physical conditions, and oral health behaviors; and Predictive the ability of IPQ-RDE to predict geriatric oral health related quality o life. Statistical analysis will include confirmatory factor analysis for examining factor structure correlations, regressions, and t-tests for validity, and Cronbach's alpha and intraclass correlatio coefficient for reliability. Behavioral interventions have not been studied that incorporate both the cognitive and emotional domains to improve older adult's oral health behavior, disease outcomes, and quality of life. This new measure of illness perception will address this need and become an important resource for oral health researchers.